1 // -*- C++ -*-
2 //===----------------------------------------------------------------------===//
3 //
4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 // See https://llvm.org/LICENSE.txt for license information.
6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //
8 //===----------------------------------------------------------------------===//
9
10 #ifndef _LIBCPP___MEMORY_UNINITIALIZED_ALGORITHMS_H
11 #define _LIBCPP___MEMORY_UNINITIALIZED_ALGORITHMS_H
12
13 #include <__algorithm/copy.h>
14 #include <__algorithm/move.h>
15 #include <__algorithm/unwrap_iter.h>
16 #include <__algorithm/unwrap_range.h>
17 #include <__config>
18 #include <__iterator/iterator_traits.h>
19 #include <__iterator/reverse_iterator.h>
20 #include <__memory/addressof.h>
21 #include <__memory/allocator_traits.h>
22 #include <__memory/construct_at.h>
23 #include <__memory/pointer_traits.h>
24 #include <__memory/voidify.h>
25 #include <__type_traits/extent.h>
26 #include <__type_traits/is_array.h>
27 #include <__type_traits/is_constant_evaluated.h>
28 #include <__type_traits/is_trivially_copy_assignable.h>
29 #include <__type_traits/is_trivially_copy_constructible.h>
30 #include <__type_traits/is_trivially_move_assignable.h>
31 #include <__type_traits/is_trivially_move_constructible.h>
32 #include <__type_traits/is_unbounded_array.h>
33 #include <__type_traits/negation.h>
34 #include <__type_traits/remove_const.h>
35 #include <__type_traits/remove_extent.h>
36 #include <__utility/exception_guard.h>
37 #include <__utility/move.h>
38 #include <__utility/pair.h>
39 #include <new>
40
41 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
42 # pragma GCC system_header
43 #endif
44
45 _LIBCPP_PUSH_MACROS
46 #include <__undef_macros>
47
48 _LIBCPP_BEGIN_NAMESPACE_STD
49
50 struct __always_false {
51 template <class... _Args>
operator__always_false52 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool operator()(_Args&&...) const _NOEXCEPT {
53 return false;
54 }
55 };
56
57 // uninitialized_copy
58
59 template <class _ValueType, class _InputIterator, class _Sentinel1, class _ForwardIterator, class _EndPredicate>
__uninitialized_copy(_InputIterator __ifirst,_Sentinel1 __ilast,_ForwardIterator __ofirst,_EndPredicate __stop_copying)60 inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator> __uninitialized_copy(
61 _InputIterator __ifirst, _Sentinel1 __ilast, _ForwardIterator __ofirst, _EndPredicate __stop_copying) {
62 _ForwardIterator __idx = __ofirst;
63 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS
64 try {
65 #endif
66 for (; __ifirst != __ilast && !__stop_copying(__idx); ++__ifirst, (void)++__idx)
67 ::new (std::__voidify(*__idx)) _ValueType(*__ifirst);
68 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS
69 } catch (...) {
70 std::__destroy(__ofirst, __idx);
71 throw;
72 }
73 #endif
74
75 return pair<_InputIterator, _ForwardIterator>(std::move(__ifirst), std::move(__idx));
76 }
77
78 template <class _InputIterator, class _ForwardIterator>
79 _LIBCPP_HIDE_FROM_ABI _ForwardIterator
uninitialized_copy(_InputIterator __ifirst,_InputIterator __ilast,_ForwardIterator __ofirst)80 uninitialized_copy(_InputIterator __ifirst, _InputIterator __ilast, _ForwardIterator __ofirst) {
81 typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType;
82 auto __result = std::__uninitialized_copy<_ValueType>(
83 std::move(__ifirst), std::move(__ilast), std::move(__ofirst), __always_false());
84 return std::move(__result.second);
85 }
86
87 // uninitialized_copy_n
88
89 template <class _ValueType, class _InputIterator, class _Size, class _ForwardIterator, class _EndPredicate>
90 inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator>
__uninitialized_copy_n(_InputIterator __ifirst,_Size __n,_ForwardIterator __ofirst,_EndPredicate __stop_copying)91 __uninitialized_copy_n(_InputIterator __ifirst, _Size __n, _ForwardIterator __ofirst, _EndPredicate __stop_copying) {
92 _ForwardIterator __idx = __ofirst;
93 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS
94 try {
95 #endif
96 for (; __n > 0 && !__stop_copying(__idx); ++__ifirst, (void)++__idx, (void)--__n)
97 ::new (std::__voidify(*__idx)) _ValueType(*__ifirst);
98 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS
99 } catch (...) {
100 std::__destroy(__ofirst, __idx);
101 throw;
102 }
103 #endif
104
105 return pair<_InputIterator, _ForwardIterator>(std::move(__ifirst), std::move(__idx));
106 }
107
108 template <class _InputIterator, class _Size, class _ForwardIterator>
109 inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator
uninitialized_copy_n(_InputIterator __ifirst,_Size __n,_ForwardIterator __ofirst)110 uninitialized_copy_n(_InputIterator __ifirst, _Size __n, _ForwardIterator __ofirst) {
111 typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType;
112 auto __result =
113 std::__uninitialized_copy_n<_ValueType>(std::move(__ifirst), __n, std::move(__ofirst), __always_false());
114 return std::move(__result.second);
115 }
116
117 // uninitialized_fill
118
119 template <class _ValueType, class _ForwardIterator, class _Sentinel, class _Tp>
120 inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator
__uninitialized_fill(_ForwardIterator __first,_Sentinel __last,const _Tp & __x)121 __uninitialized_fill(_ForwardIterator __first, _Sentinel __last, const _Tp& __x) {
122 _ForwardIterator __idx = __first;
123 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS
124 try {
125 #endif
126 for (; __idx != __last; ++__idx)
127 ::new (std::__voidify(*__idx)) _ValueType(__x);
128 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS
129 } catch (...) {
130 std::__destroy(__first, __idx);
131 throw;
132 }
133 #endif
134
135 return __idx;
136 }
137
138 template <class _ForwardIterator, class _Tp>
139 inline _LIBCPP_HIDE_FROM_ABI void
uninitialized_fill(_ForwardIterator __first,_ForwardIterator __last,const _Tp & __x)140 uninitialized_fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __x) {
141 typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType;
142 (void)std::__uninitialized_fill<_ValueType>(__first, __last, __x);
143 }
144
145 // uninitialized_fill_n
146
147 template <class _ValueType, class _ForwardIterator, class _Size, class _Tp>
148 inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator
__uninitialized_fill_n(_ForwardIterator __first,_Size __n,const _Tp & __x)149 __uninitialized_fill_n(_ForwardIterator __first, _Size __n, const _Tp& __x) {
150 _ForwardIterator __idx = __first;
151 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS
152 try {
153 #endif
154 for (; __n > 0; ++__idx, (void)--__n)
155 ::new (std::__voidify(*__idx)) _ValueType(__x);
156 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS
157 } catch (...) {
158 std::__destroy(__first, __idx);
159 throw;
160 }
161 #endif
162
163 return __idx;
164 }
165
166 template <class _ForwardIterator, class _Size, class _Tp>
167 inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator
uninitialized_fill_n(_ForwardIterator __first,_Size __n,const _Tp & __x)168 uninitialized_fill_n(_ForwardIterator __first, _Size __n, const _Tp& __x) {
169 typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType;
170 return std::__uninitialized_fill_n<_ValueType>(__first, __n, __x);
171 }
172
173 #if _LIBCPP_STD_VER >= 17
174
175 // uninitialized_default_construct
176
177 template <class _ValueType, class _ForwardIterator, class _Sentinel>
178 inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator
__uninitialized_default_construct(_ForwardIterator __first,_Sentinel __last)179 __uninitialized_default_construct(_ForwardIterator __first, _Sentinel __last) {
180 auto __idx = __first;
181 # ifndef _LIBCPP_HAS_NO_EXCEPTIONS
182 try {
183 # endif
184 for (; __idx != __last; ++__idx)
185 ::new (std::__voidify(*__idx)) _ValueType;
186 # ifndef _LIBCPP_HAS_NO_EXCEPTIONS
187 } catch (...) {
188 std::__destroy(__first, __idx);
189 throw;
190 }
191 # endif
192
193 return __idx;
194 }
195
196 template <class _ForwardIterator>
uninitialized_default_construct(_ForwardIterator __first,_ForwardIterator __last)197 inline _LIBCPP_HIDE_FROM_ABI void uninitialized_default_construct(_ForwardIterator __first, _ForwardIterator __last) {
198 using _ValueType = typename iterator_traits<_ForwardIterator>::value_type;
199 (void)std::__uninitialized_default_construct<_ValueType>(std::move(__first), std::move(__last));
200 }
201
202 // uninitialized_default_construct_n
203
204 template <class _ValueType, class _ForwardIterator, class _Size>
__uninitialized_default_construct_n(_ForwardIterator __first,_Size __n)205 inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator __uninitialized_default_construct_n(_ForwardIterator __first, _Size __n) {
206 auto __idx = __first;
207 # ifndef _LIBCPP_HAS_NO_EXCEPTIONS
208 try {
209 # endif
210 for (; __n > 0; ++__idx, (void)--__n)
211 ::new (std::__voidify(*__idx)) _ValueType;
212 # ifndef _LIBCPP_HAS_NO_EXCEPTIONS
213 } catch (...) {
214 std::__destroy(__first, __idx);
215 throw;
216 }
217 # endif
218
219 return __idx;
220 }
221
222 template <class _ForwardIterator, class _Size>
uninitialized_default_construct_n(_ForwardIterator __first,_Size __n)223 inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator uninitialized_default_construct_n(_ForwardIterator __first, _Size __n) {
224 using _ValueType = typename iterator_traits<_ForwardIterator>::value_type;
225 return std::__uninitialized_default_construct_n<_ValueType>(std::move(__first), __n);
226 }
227
228 // uninitialized_value_construct
229
230 template <class _ValueType, class _ForwardIterator, class _Sentinel>
231 inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator
__uninitialized_value_construct(_ForwardIterator __first,_Sentinel __last)232 __uninitialized_value_construct(_ForwardIterator __first, _Sentinel __last) {
233 auto __idx = __first;
234 # ifndef _LIBCPP_HAS_NO_EXCEPTIONS
235 try {
236 # endif
237 for (; __idx != __last; ++__idx)
238 ::new (std::__voidify(*__idx)) _ValueType();
239 # ifndef _LIBCPP_HAS_NO_EXCEPTIONS
240 } catch (...) {
241 std::__destroy(__first, __idx);
242 throw;
243 }
244 # endif
245
246 return __idx;
247 }
248
249 template <class _ForwardIterator>
uninitialized_value_construct(_ForwardIterator __first,_ForwardIterator __last)250 inline _LIBCPP_HIDE_FROM_ABI void uninitialized_value_construct(_ForwardIterator __first, _ForwardIterator __last) {
251 using _ValueType = typename iterator_traits<_ForwardIterator>::value_type;
252 (void)std::__uninitialized_value_construct<_ValueType>(std::move(__first), std::move(__last));
253 }
254
255 // uninitialized_value_construct_n
256
257 template <class _ValueType, class _ForwardIterator, class _Size>
__uninitialized_value_construct_n(_ForwardIterator __first,_Size __n)258 inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator __uninitialized_value_construct_n(_ForwardIterator __first, _Size __n) {
259 auto __idx = __first;
260 # ifndef _LIBCPP_HAS_NO_EXCEPTIONS
261 try {
262 # endif
263 for (; __n > 0; ++__idx, (void)--__n)
264 ::new (std::__voidify(*__idx)) _ValueType();
265 # ifndef _LIBCPP_HAS_NO_EXCEPTIONS
266 } catch (...) {
267 std::__destroy(__first, __idx);
268 throw;
269 }
270 # endif
271
272 return __idx;
273 }
274
275 template <class _ForwardIterator, class _Size>
uninitialized_value_construct_n(_ForwardIterator __first,_Size __n)276 inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator uninitialized_value_construct_n(_ForwardIterator __first, _Size __n) {
277 using _ValueType = typename iterator_traits<_ForwardIterator>::value_type;
278 return std::__uninitialized_value_construct_n<_ValueType>(std::move(__first), __n);
279 }
280
281 // uninitialized_move
282
283 template <class _ValueType,
284 class _InputIterator,
285 class _Sentinel1,
286 class _ForwardIterator,
287 class _EndPredicate,
288 class _IterMove>
__uninitialized_move(_InputIterator __ifirst,_Sentinel1 __ilast,_ForwardIterator __ofirst,_EndPredicate __stop_moving,_IterMove __iter_move)289 inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator> __uninitialized_move(
290 _InputIterator __ifirst,
291 _Sentinel1 __ilast,
292 _ForwardIterator __ofirst,
293 _EndPredicate __stop_moving,
294 _IterMove __iter_move) {
295 auto __idx = __ofirst;
296 # ifndef _LIBCPP_HAS_NO_EXCEPTIONS
297 try {
298 # endif
299 for (; __ifirst != __ilast && !__stop_moving(__idx); ++__idx, (void)++__ifirst) {
300 ::new (std::__voidify(*__idx)) _ValueType(__iter_move(__ifirst));
301 }
302 # ifndef _LIBCPP_HAS_NO_EXCEPTIONS
303 } catch (...) {
304 std::__destroy(__ofirst, __idx);
305 throw;
306 }
307 # endif
308
309 return {std::move(__ifirst), std::move(__idx)};
310 }
311
312 template <class _InputIterator, class _ForwardIterator>
313 inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator
uninitialized_move(_InputIterator __ifirst,_InputIterator __ilast,_ForwardIterator __ofirst)314 uninitialized_move(_InputIterator __ifirst, _InputIterator __ilast, _ForwardIterator __ofirst) {
315 using _ValueType = typename iterator_traits<_ForwardIterator>::value_type;
316 auto __iter_move = [](auto&& __iter) -> decltype(auto) { return std::move(*__iter); };
317
318 auto __result = std::__uninitialized_move<_ValueType>(
319 std::move(__ifirst), std::move(__ilast), std::move(__ofirst), __always_false(), __iter_move);
320 return std::move(__result.second);
321 }
322
323 // uninitialized_move_n
324
325 template <class _ValueType,
326 class _InputIterator,
327 class _Size,
328 class _ForwardIterator,
329 class _EndPredicate,
330 class _IterMove>
__uninitialized_move_n(_InputIterator __ifirst,_Size __n,_ForwardIterator __ofirst,_EndPredicate __stop_moving,_IterMove __iter_move)331 inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator> __uninitialized_move_n(
332 _InputIterator __ifirst, _Size __n, _ForwardIterator __ofirst, _EndPredicate __stop_moving, _IterMove __iter_move) {
333 auto __idx = __ofirst;
334 # ifndef _LIBCPP_HAS_NO_EXCEPTIONS
335 try {
336 # endif
337 for (; __n > 0 && !__stop_moving(__idx); ++__idx, (void)++__ifirst, --__n)
338 ::new (std::__voidify(*__idx)) _ValueType(__iter_move(__ifirst));
339 # ifndef _LIBCPP_HAS_NO_EXCEPTIONS
340 } catch (...) {
341 std::__destroy(__ofirst, __idx);
342 throw;
343 }
344 # endif
345
346 return {std::move(__ifirst), std::move(__idx)};
347 }
348
349 template <class _InputIterator, class _Size, class _ForwardIterator>
350 inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator>
uninitialized_move_n(_InputIterator __ifirst,_Size __n,_ForwardIterator __ofirst)351 uninitialized_move_n(_InputIterator __ifirst, _Size __n, _ForwardIterator __ofirst) {
352 using _ValueType = typename iterator_traits<_ForwardIterator>::value_type;
353 auto __iter_move = [](auto&& __iter) -> decltype(auto) { return std::move(*__iter); };
354
355 return std::__uninitialized_move_n<_ValueType>(
356 std::move(__ifirst), __n, std::move(__ofirst), __always_false(), __iter_move);
357 }
358
359 // TODO: Rewrite this to iterate left to right and use reverse_iterators when calling
360 // Destroys every element in the range [first, last) FROM RIGHT TO LEFT using allocator
361 // destruction. If elements are themselves C-style arrays, they are recursively destroyed
362 // in the same manner.
363 //
364 // This function assumes that destructors do not throw, and that the allocator is bound to
365 // the correct type.
366 template <class _Alloc,
367 class _BidirIter,
368 class = __enable_if_t< __has_bidirectional_iterator_category<_BidirIter>::value >>
369 _LIBCPP_HIDE_FROM_ABI constexpr void
__allocator_destroy_multidimensional(_Alloc & __alloc,_BidirIter __first,_BidirIter __last)370 __allocator_destroy_multidimensional(_Alloc& __alloc, _BidirIter __first, _BidirIter __last) noexcept {
371 using _ValueType = typename iterator_traits<_BidirIter>::value_type;
372 static_assert(is_same_v<typename allocator_traits<_Alloc>::value_type, _ValueType>,
373 "The allocator should already be rebound to the correct type");
374
375 if (__first == __last)
376 return;
377
378 if constexpr (is_array_v<_ValueType>) {
379 static_assert(!__libcpp_is_unbounded_array<_ValueType>::value,
380 "arrays of unbounded arrays don't exist, but if they did we would mess up here");
381
382 using _Element = remove_extent_t<_ValueType>;
383 __allocator_traits_rebind_t<_Alloc, _Element> __elem_alloc(__alloc);
384 do {
385 --__last;
386 decltype(auto) __array = *__last;
387 std::__allocator_destroy_multidimensional(__elem_alloc, __array, __array + extent_v<_ValueType>);
388 } while (__last != __first);
389 } else {
390 do {
391 --__last;
392 allocator_traits<_Alloc>::destroy(__alloc, std::addressof(*__last));
393 } while (__last != __first);
394 }
395 }
396
397 // Constructs the object at the given location using the allocator's construct method.
398 //
399 // If the object being constructed is an array, each element of the array is allocator-constructed,
400 // recursively. If an exception is thrown during the construction of an array, the initialized
401 // elements are destroyed in reverse order of initialization using allocator destruction.
402 //
403 // This function assumes that the allocator is bound to the correct type.
404 template <class _Alloc, class _Tp>
__allocator_construct_at_multidimensional(_Alloc & __alloc,_Tp * __loc)405 _LIBCPP_HIDE_FROM_ABI constexpr void __allocator_construct_at_multidimensional(_Alloc& __alloc, _Tp* __loc) {
406 static_assert(is_same_v<typename allocator_traits<_Alloc>::value_type, _Tp>,
407 "The allocator should already be rebound to the correct type");
408
409 if constexpr (is_array_v<_Tp>) {
410 using _Element = remove_extent_t<_Tp>;
411 __allocator_traits_rebind_t<_Alloc, _Element> __elem_alloc(__alloc);
412 size_t __i = 0;
413 _Tp& __array = *__loc;
414
415 // If an exception is thrown, destroy what we have constructed so far in reverse order.
416 auto __guard = std::__make_exception_guard([&]() {
417 std::__allocator_destroy_multidimensional(__elem_alloc, __array, __array + __i);
418 });
419
420 for (; __i != extent_v<_Tp>; ++__i) {
421 std::__allocator_construct_at_multidimensional(__elem_alloc, std::addressof(__array[__i]));
422 }
423 __guard.__complete();
424 } else {
425 allocator_traits<_Alloc>::construct(__alloc, __loc);
426 }
427 }
428
429 // Constructs the object at the given location using the allocator's construct method, passing along
430 // the provided argument.
431 //
432 // If the object being constructed is an array, the argument is also assumed to be an array. Each
433 // each element of the array being constructed is allocator-constructed from the corresponding
434 // element of the argument array. If an exception is thrown during the construction of an array,
435 // the initialized elements are destroyed in reverse order of initialization using allocator
436 // destruction.
437 //
438 // This function assumes that the allocator is bound to the correct type.
439 template <class _Alloc, class _Tp, class _Arg>
440 _LIBCPP_HIDE_FROM_ABI constexpr void
__allocator_construct_at_multidimensional(_Alloc & __alloc,_Tp * __loc,_Arg const & __arg)441 __allocator_construct_at_multidimensional(_Alloc& __alloc, _Tp* __loc, _Arg const& __arg) {
442 static_assert(is_same_v<typename allocator_traits<_Alloc>::value_type, _Tp>,
443 "The allocator should already be rebound to the correct type");
444
445 if constexpr (is_array_v<_Tp>) {
446 static_assert(is_array_v<_Arg>,
447 "Provided non-array initialization argument to __allocator_construct_at_multidimensional when "
448 "trying to construct an array.");
449
450 using _Element = remove_extent_t<_Tp>;
451 __allocator_traits_rebind_t<_Alloc, _Element> __elem_alloc(__alloc);
452 size_t __i = 0;
453 _Tp& __array = *__loc;
454
455 // If an exception is thrown, destroy what we have constructed so far in reverse order.
456 auto __guard = std::__make_exception_guard([&]() {
457 std::__allocator_destroy_multidimensional(__elem_alloc, __array, __array + __i);
458 });
459 for (; __i != extent_v<_Tp>; ++__i) {
460 std::__allocator_construct_at_multidimensional(__elem_alloc, std::addressof(__array[__i]), __arg[__i]);
461 }
462 __guard.__complete();
463 } else {
464 allocator_traits<_Alloc>::construct(__alloc, __loc, __arg);
465 }
466 }
467
468 // Given a range starting at it and containing n elements, initializes each element in the
469 // range from left to right using the construct method of the allocator (rebound to the
470 // correct type).
471 //
472 // If an exception is thrown, the initialized elements are destroyed in reverse order of
473 // initialization using allocator_traits destruction. If the elements in the range are C-style
474 // arrays, they are initialized element-wise using allocator construction, and recursively so.
475 template <class _Alloc,
476 class _BidirIter,
477 class _Tp,
478 class _Size = typename iterator_traits<_BidirIter>::difference_type>
479 _LIBCPP_HIDE_FROM_ABI constexpr void
__uninitialized_allocator_fill_n_multidimensional(_Alloc & __alloc,_BidirIter __it,_Size __n,_Tp const & __value)480 __uninitialized_allocator_fill_n_multidimensional(_Alloc& __alloc, _BidirIter __it, _Size __n, _Tp const& __value) {
481 using _ValueType = typename iterator_traits<_BidirIter>::value_type;
482 __allocator_traits_rebind_t<_Alloc, _ValueType> __value_alloc(__alloc);
483 _BidirIter __begin = __it;
484
485 // If an exception is thrown, destroy what we have constructed so far in reverse order.
486 auto __guard =
487 std::__make_exception_guard([&]() { std::__allocator_destroy_multidimensional(__value_alloc, __begin, __it); });
488 for (; __n != 0; --__n, ++__it) {
489 std::__allocator_construct_at_multidimensional(__value_alloc, std::addressof(*__it), __value);
490 }
491 __guard.__complete();
492 }
493
494 // Same as __uninitialized_allocator_fill_n_multidimensional, but doesn't pass any initialization argument
495 // to the allocator's construct method, which results in value initialization.
496 template <class _Alloc, class _BidirIter, class _Size = typename iterator_traits<_BidirIter>::difference_type>
497 _LIBCPP_HIDE_FROM_ABI constexpr void
__uninitialized_allocator_value_construct_n_multidimensional(_Alloc & __alloc,_BidirIter __it,_Size __n)498 __uninitialized_allocator_value_construct_n_multidimensional(_Alloc& __alloc, _BidirIter __it, _Size __n) {
499 using _ValueType = typename iterator_traits<_BidirIter>::value_type;
500 __allocator_traits_rebind_t<_Alloc, _ValueType> __value_alloc(__alloc);
501 _BidirIter __begin = __it;
502
503 // If an exception is thrown, destroy what we have constructed so far in reverse order.
504 auto __guard =
505 std::__make_exception_guard([&]() { std::__allocator_destroy_multidimensional(__value_alloc, __begin, __it); });
506 for (; __n != 0; --__n, ++__it) {
507 std::__allocator_construct_at_multidimensional(__value_alloc, std::addressof(*__it));
508 }
509 __guard.__complete();
510 }
511
512 #endif // _LIBCPP_STD_VER >= 17
513
514 // Destroy all elements in [__first, __last) from left to right using allocator destruction.
515 template <class _Alloc, class _Iter, class _Sent>
516 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
__allocator_destroy(_Alloc & __alloc,_Iter __first,_Sent __last)517 __allocator_destroy(_Alloc& __alloc, _Iter __first, _Sent __last) {
518 for (; __first != __last; ++__first)
519 allocator_traits<_Alloc>::destroy(__alloc, std::__to_address(__first));
520 }
521
522 template <class _Alloc, class _Iter>
523 class _AllocatorDestroyRangeReverse {
524 public:
525 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14
_AllocatorDestroyRangeReverse(_Alloc & __alloc,_Iter & __first,_Iter & __last)526 _AllocatorDestroyRangeReverse(_Alloc& __alloc, _Iter& __first, _Iter& __last)
527 : __alloc_(__alloc), __first_(__first), __last_(__last) {}
528
operator()529 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void operator()() const {
530 std::__allocator_destroy(__alloc_, std::reverse_iterator<_Iter>(__last_), std::reverse_iterator<_Iter>(__first_));
531 }
532
533 private:
534 _Alloc& __alloc_;
535 _Iter& __first_;
536 _Iter& __last_;
537 };
538
539 // Copy-construct [__first1, __last1) in [__first2, __first2 + N), where N is distance(__first1, __last1).
540 //
541 // The caller has to ensure that __first2 can hold at least N uninitialized elements. If an exception is thrown the
542 // already copied elements are destroyed in reverse order of their construction.
543 template <class _Alloc, class _Iter1, class _Sent1, class _Iter2>
544 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Iter2
__uninitialized_allocator_copy_impl(_Alloc & __alloc,_Iter1 __first1,_Sent1 __last1,_Iter2 __first2)545 __uninitialized_allocator_copy_impl(_Alloc& __alloc, _Iter1 __first1, _Sent1 __last1, _Iter2 __first2) {
546 auto __destruct_first = __first2;
547 auto __guard =
548 std::__make_exception_guard(_AllocatorDestroyRangeReverse<_Alloc, _Iter2>(__alloc, __destruct_first, __first2));
549 while (__first1 != __last1) {
550 allocator_traits<_Alloc>::construct(__alloc, std::__to_address(__first2), *__first1);
551 ++__first1;
552 ++__first2;
553 }
554 __guard.__complete();
555 return __first2;
556 }
557
558 template <class _Alloc, class _Type>
559 struct __allocator_has_trivial_copy_construct : _Not<__has_construct<_Alloc, _Type*, const _Type&> > {};
560
561 template <class _Type>
562 struct __allocator_has_trivial_copy_construct<allocator<_Type>, _Type> : true_type {};
563
564 template <class _Alloc,
565 class _In,
566 class _RawTypeIn = __remove_const_t<_In>,
567 class _Out,
568 __enable_if_t<
569 // using _RawTypeIn because of the allocator<T const> extension
570 is_trivially_copy_constructible<_RawTypeIn>::value && is_trivially_copy_assignable<_RawTypeIn>::value &&
571 is_same<__remove_const_t<_In>, __remove_const_t<_Out> >::value &&
572 __allocator_has_trivial_copy_construct<_Alloc, _RawTypeIn>::value>* = nullptr>
573 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Out*
574 __uninitialized_allocator_copy_impl(_Alloc&, _In* __first1, _In* __last1, _Out* __first2) {
575 // TODO: Remove the const_cast once we drop support for std::allocator<T const>
576 if (__libcpp_is_constant_evaluated()) {
577 while (__first1 != __last1) {
578 std::__construct_at(std::__to_address(__first2), *__first1);
579 ++__first1;
580 ++__first2;
581 }
582 return __first2;
583 } else {
584 return std::copy(__first1, __last1, const_cast<_RawTypeIn*>(__first2));
585 }
586 }
587
588 template <class _Alloc, class _Iter1, class _Sent1, class _Iter2>
589 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Iter2
590 __uninitialized_allocator_copy(_Alloc& __alloc, _Iter1 __first1, _Sent1 __last1, _Iter2 __first2) {
591 auto __unwrapped_range = std::__unwrap_range(__first1, __last1);
592 auto __result = std::__uninitialized_allocator_copy_impl(
593 __alloc, __unwrapped_range.first, __unwrapped_range.second, std::__unwrap_iter(__first2));
594 return std::__rewrap_iter(__first2, __result);
595 }
596
597 // Move-construct the elements [__first1, __last1) into [__first2, __first2 + N)
598 // if the move constructor is noexcept, where N is distance(__first1, __last1).
599 //
600 // Otherwise try to copy all elements. If an exception is thrown the already copied
601 // elements are destroyed in reverse order of their construction.
602 template <class _Alloc, class _Iter1, class _Sent1, class _Iter2>
603 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Iter2
604 __uninitialized_allocator_move_if_noexcept(_Alloc& __alloc, _Iter1 __first1, _Sent1 __last1, _Iter2 __first2) {
605 static_assert(__is_cpp17_move_insertable<_Alloc>::value,
606 "The specified type does not meet the requirements of Cpp17MoveInsertable");
607 auto __destruct_first = __first2;
608 auto __guard =
609 std::__make_exception_guard(_AllocatorDestroyRangeReverse<_Alloc, _Iter2>(__alloc, __destruct_first, __first2));
610 while (__first1 != __last1) {
611 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS
612 allocator_traits<_Alloc>::construct(__alloc, std::__to_address(__first2), std::move_if_noexcept(*__first1));
613 #else
614 allocator_traits<_Alloc>::construct(__alloc, std::__to_address(__first2), std::move(*__first1));
615 #endif
616 ++__first1;
617 ++__first2;
618 }
619 __guard.__complete();
620 return __first2;
621 }
622
623 template <class _Alloc, class _Type>
624 struct __allocator_has_trivial_move_construct : _Not<__has_construct<_Alloc, _Type*, _Type&&> > {};
625
626 template <class _Type>
627 struct __allocator_has_trivial_move_construct<allocator<_Type>, _Type> : true_type {};
628
629 #ifndef _LIBCPP_COMPILER_GCC
630 template <
631 class _Alloc,
632 class _Iter1,
633 class _Iter2,
634 class _Type = typename iterator_traits<_Iter1>::value_type,
635 class = __enable_if_t<is_trivially_move_constructible<_Type>::value && is_trivially_move_assignable<_Type>::value &&
636 __allocator_has_trivial_move_construct<_Alloc, _Type>::value> >
637 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Iter2
638 __uninitialized_allocator_move_if_noexcept(_Alloc&, _Iter1 __first1, _Iter1 __last1, _Iter2 __first2) {
639 if (__libcpp_is_constant_evaluated()) {
640 while (__first1 != __last1) {
641 std::__construct_at(std::__to_address(__first2), std::move(*__first1));
642 ++__first1;
643 ++__first2;
644 }
645 return __first2;
646 } else {
647 return std::move(__first1, __last1, __first2);
648 }
649 }
650 #endif // _LIBCPP_COMPILER_GCC
651
652 _LIBCPP_END_NAMESPACE_STD
653
654 _LIBCPP_POP_MACROS
655
656 #endif // _LIBCPP___MEMORY_UNINITIALIZED_ALGORITHMS_H
657